Catapleiite (Na₂ZrSi₃O₉·2H₂O) is a dimorph of gaidonnayite rarely found by itself. Its name derives from the Greek words "κατα" (kata) and "πλειον" (pleion) meaning "with more" as it is mostly accompanied by a number of rare minerals. When pure it is colorless, but it is most often seen as a tan, brownish-red, light yellow, dark brown, flesh red or orangish in color. It is mostly found on Låven Island, Norway. Its hardness on the Mohs scale is around 5.5–6. It has a monoclinic crystal system.^[1][2]

Catapleiite
Catapleiite.Locality: Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry; Carrière Mont Saint-Hilaire), Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada
General
Category	Mineral
Formula (repeating unit)	Na2ZrSi3O9·2H2O
IMA symbol	Ctp
Identification
Color	Colorless, tan, brownish-red, light yellow, dark brown, flesh red, orangish
Mohs scale hardness	5.5–6
Luster	Vitreous, dull
Specific gravity	2.65–2.9